Anatomic Study On The Autografts For Arthroscopic ACL Reconstruction And Its Clinical Application

Objective: To observe the tendons of patella, gracilis, and semitendinosus in normal adult cadavers, and measure the insertions, the length, the cross section area and the biomechanics in order to provide the anatomical basis for clinical application.Methods: Fresh lower limb specimens of nineteen male Chinese were selected for the anatomic study on the insertion, the length, the cross section area of the three tendons. Four specimens of all were applied to measure the biomechanics. The methods included: (1) observing the pathway of the saphenous nerve and the infrapatellar branch, (2) observing the appearance of the insertions of the tendons, and measuring the length and the cross section area of every tendon,(3) measuring the biomechanics of the autografts for ACL reconstruction.Results: (1)The saphenous nerve emerges from the inferior border of sartorius, which intersects with the gracilis tendon . The infrapatellar branch goes along the medial border of the patella, which supplies the anteromedial area of the knee.(2) The patellar tendon is located between the inferior pole of patellaand the tibial tubercle, which has a good size(5.16cm±0.34cm in length, 2.93cm±0.25cm in width, and 3.14 mm±0.35mm in thickness). The tendons of gracilis, semitendinosus and sartorius constitute the pes anserinus. The total length of the tendons of gracilis and semitendinosus is 22.05cm±3.02cm and 25.27cm±2.92cm respectively. The cross section area of the two is 10.30mntf±1.13 mm2 and 15.03mm*tl.98mm2 respectively.(3) The biomechanics of the three kinds of autografts are different. The maximum load of 1 Omm-in-width B-PT-B is 1496.77N±142.35N, and the other two are 561.15N±100.77N and 920.48N±183.54N respectively. Conclusions: (1) The selection of the autografts should be decided according to the physical properties and the anatomical features of each tendon. Comparatively speaking, the hamstrings (including two strands of gracilis tendon and two strands of semitendinosus tendon) taken as autografts are superior to B-PT-B. It has been trend to apply HS for ACL reconstruction.(2) The arcuated incision inferior and medial to tibial condyle can avoid injuring saphenous nerve and infrapatellar branch; the horizontal incision based on the junction of the middle and distal third portion of the patellar tendon can decrease the injuries of the infrapatellar branch.(3) Inciding the main affiliated bundle carefully in order to maintain the integration of semitendinosus tendon. Bluntly dissecting the patellar tendon to avoid dissevering the fibers, meanwhile the bone blocks should be taken carefully in order to get a good size.